Process for the generation of acetylene from calcium carbide and water



June 17, 1947.

H. HOLLER ET AL PROCESS FOR THE GENERATION OF AGETYLENE FROM CALCIUM CARBIDE AND WATER Filed March 6, 1939 Wafer 1 (Less #m rm! gzggrequired in e comp/e1: the reqcfian) v q flail/lent Generafor .Separqfar on; (a/dam Calcium I Carbide Hqdroxide Residue Wafer .Ca/aum Carbide required fv comp/efe fire read/kn) v Drq Mal: Generafar I I --m i Separafvr DrI/ Calcium Calcium Carbide Hydroxide figs/due Wef' 'Acefl/lene Genermvr Wifer Cale/um (less #m flu! required in v comp/dc flze reacfion) Dfl/ Jail lure Ge nerafar Separafor 0n] Ca/cil/m Calcium fart He Hydroxide fies/due war - Generafar E Wafer (Less fbamlnf required in q comp/defile L read/on l- 7 Dry M1818 General Sepamfvr Dry Calm/m Calcium (q/abide Hqdroxide Residue A NEYS hydroxide Patented quarrel 7,1947

PROCESS FOR THE GENERATION F ACETYLENE FROM CALCIUM CARBIDE AND WATER Hermann Holler, Frankfort-on-the-Main, and

Otto Mues, Georgsmarienhutte, near Osnabruck, Germany; vested in the Attorney General of the United States Application March 6, 1939, Serial No. 260,146 In Germany March 5, 1938 Sections 3 and 14, Public Law 690, August 8, 1946. Patent expires March 5, 1958 y 2 Claims. (01. 48216) (Granted under the provisions of sec. 14, act of March 2, 1927; 357 O. G. 5)

the large amount of water necessary for removal of the heat produced is disadvantageous because on the one hand it causes a considerable loss of and, on the other hand the calcium produced is obtained in the form of a thus be separated and acetylene,

mud-like mass and can by reacting with a limited amount of water only a dry-generator so as to obtain practically dry calcium hydroxide, and separating the incom- Worked up only with difiiculty. Processes have already been proposed whereby a practically dry calcium hydroxide can be obtained by adding to the carbide, generally present in the form of pieces, only a limited amount of water, part of which serves for the chemical reaction, while the evaporation of the rest absorbs and removes the heat of reaction. 1

These dry-gasification" processes are carried out as follows: during the entire reaction, namely until the evolution of gas from the carbide is practically complete, the pieces of carbide and the calcium hydroxide formed remain together and when the reaction is finished the pulverulent lime is removed from the generator. Since, however, pari passu with the decreasing amount of carbide in the mixture of calcium carbide and calcium hydroxide the speed of evolution of gas continuously diminishes owing to the fact that the amount and surface of the car-bide continuously decrease, it is absolutely essential to use a generator for the complete gasification in which the path of single grains of calcium carbide is as long as possible. It is, therefore, necessary to use comparatively large generators which are costly in respect of construction and maintenance and may be rather complicated. v

Another difliculty in such dry-gasification process resides in the fact that the amount of water to be added must always be controlled in accord with the amount of carbide present in the generator in order to obtain the practically dry calcium hydroxide desired. Hence such'process requires constant and exact attention, particularly with reference to the water supply which, if not regulated, may lead to the production of moist slaked lime or to the presence of still ungasifled particles of carbide in the residue.

The present invention avoids these drawbacks pletely reacting remaining portion of the carbide, not yet gasifled, fromthe hydroxide formed, and removing it from the generator to be introduced either into another generator or into the same generator. V

Various processes are known for separating in dry-generators the carbide from the hydroxide immediately after the latter has been formed. In this case the layer of calcium hydroxide surrounding each grain of calcium carbide is removed so that the water in the generator can have access to each grain as easily as possible. -The carbide is, however, not removed from the generator, but remains therein together with the hydroxide until the gasification process in the eneratoris complete. I

Another process is known, in which a metal oxide is used as a carrier for a thin carbide coating. The oxide particles forming the carriers are reconducted in a cycle into the apparatus for producing calcium carbide after the gasiflcation of the carbide coating is complete. In view of the Fig. 4 is a flow diagram illustrating another modification of the invention.

In the present invention as shown in Fig. 1, at a certain moment the unreacted particles of carbide remaining after the main portion thereof has been gasifled may be removed from the generator, after having been separated from the calcium hydroxide, and these carbide particles may be then subjected to further reaction with water in any desired manner, as shown in Fig. 2. If this carbide remainder is gasified separately, an excess of water may be used, as shown in Fig. 3, so that the lime is obtained in this case in.the form of mud. By such a subdivision of the gasiflcation process, a certain, amount of the mud-like calcium hydroxide is produced; however, this amount is very small in comparison with the amount of dry lime obtained so that, compared with the simplification of the construction of the generator as well as with the economical advantages attained thereby it is of little importance.

Furthermore, by the premature removal of a part of the carbide it, is unnecessary to control .pieces of the carbide remain to be gasified. .In

this case the calcium hydroxide is then suitably screened from the carbide, so that the hydroxide is caused to fall into a collecting vessel or the like from which it may be removed and further worked up for use as fertilizer or it is stored in bags, whereas the remaining pieces of carbide, mixed, if desired, with fresh carbide, are reconducted into either the dry-generator, as shown in Fig. .4, or into a wet-generator, as shown in Fig. 3, of known construction which operates with an excess of water. V

Alternatively, the calcium hydroxide may be separated from the ungasified carbide by causing a current of gas to act in the manner of a sifting current; preferably, however, a circulating curseparation of the carbide from the calcium hydroxide, or in an intermittent separation of the two compounds. Furthermore, the carbide particles may either be finally gasified immediately 4 We claim: l 1. In a process for the production of acetylene and substantially dry calcium hydroxide by react- 'ing" calcium carbide with a limited amount of react all of said carbide so that no excess of water occurs in the generator and so thatthe calcium unreacted particles of the carbide from the cal-,

after separation of the hydroxide or they may be brought into a, collecting chamber from which they are introduced, as required, into the generator in which the gasification occurs.

hydroxide formed is always obtained in a substantially dry pulverulent state, separating any remaining unreacted particles of the carbide from the calcium hydroxide, removing, collecting and again introducing such remaining particles oi carbide into the inlet portidh of said dry-generator.

2. In the process for the production of acetyl- I one and substantially dry calcium hydroxide by treating calcium carbide with a Iimited amount of water in a dry-generator, the steps which comprise reacting only the main portion of the carbide introduced into the dry-generator with such a limited amount of water that no excess of water occurs in the generator and the calcium hydroxide formed is always obtained in a substantially dry pulverulent state, separating any remaining cium hydroxide, removing and again introducing such separated particles of carbide into said drygenerator together with freshc'arbide. a a

- HERMANN HOLDER.

o'r'ro MUES.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 541,429 Dickerson June 18, 1895 575,677 Fuller Jan. 19, 1897 1,872,741 Jane Aug. 23, 1932 2,122,889 Mues July 5, 1938 1,996,185 Wulii Apr. 2, 1935 Re. 20,527 Weibezahn Oct. 5, 1937 1,947,120 Weibezahn Feb. 13, 1934 2,180,085 Holler Nov. 14, 1939 

